Devstack displays only text on port 5000

I'm trying to get into OpenStack and after learning the basics I decided to install DevStack on a ESXi VM. The OS is Ubuntu 14.04. I have followed the tutorial found here: http://docs.openstack.org/developer/devstack/ (http://docs.openstack.org/developer/d...)

The problem is that after setting everything up, when trying to connect to Horizon on port 5000, all I get is the following text: